The present invention relates generally to polynorbornene and cyclotriphosphazene compositions.
A large number of polymers containing a variety of phosphazene groups have been prepared in the past several decades. The focus of these efforts has been directed to the incorporation of phosphazene or polyphosphazene into organic or inorganic polymer backbones. Numerous polymer compositions containing phosphazene groups or polyphosphazene backbones are known which contain linear phosphazene or polyphosphazene structures. See, for example, Hybrid inorganic-organic polymers derived from organofunctional phosphazenes. Allen, C. W. NTIS Report (TR-7; Order No. AD-A183612) Gov. Rep. Announce. Index (U. S.) 1987, 87(23), Abstr. No. 753,600.
Phosphazene-containing compositions are useful in a variety of applications including elastomers, optical materials, electrically conductive materials, biomedical materials, compatibilizing agents, surfactants, additives for coatings, and flame retardants. The electronic structure of a phosphazene-containing material is critical as to the chemical, as well as physical, properties of a material made of such phosphazene-containing material. For example, the electric conductivity of a phosphazene-containing material, which largely reflects the ease of the electrons to flow along the molecular backbone of such material, correlates positively to the content of xcfx80-stacking structure in the molecular backbone of such material. See, for example, xe2x80x9cElectrically conductive phosphazene polymer compositionsxe2x80x9d Jpn. Kokai Tokkyo Koho by Sato (1993); xe2x80x9cPolyphosphazenes bearing polymerizable pyrrole, thiophene and furan side groups: synthesis and chemical oxidationxe2x80x9d by Allcock, et al., NTIS. Report (TR-68; Order No. AD-A249747) Gov. Rep. Announce. Index (U. S.) 1992, 92(16), Abstr. No. 243,408; xe2x80x9cElectrically conductive polyorganophosphazenesxe2x80x9d. Jpn. Kokai Tokkyo Koho by Kajiwara, et al., (1989). Hence, the creation of a r-stacking structure or modulation of the existing xcfx80-stacking structure in a composition will affect the electrical conductivity of the composition. Similarly, the creation of a xcfx80-stacking structure or modulation of the existing xcfx80-stacking structure in a composition will affect the heat-conductivity of the composition. Moreover, linear or non-linear optical properties of an optical material can be affected by the modulation of the electronic properties of the material.
It would therefore be advantageous to develop new polymer compositions having phosphazene or polyphosphazene groups or moieties, utilizing one or more of these properties.
Cyclotriphosphazene compositions are known. For example, U.S. Pat. No. 4,668,589 to Kumar et al. discloses an adduct of epoxy resin and cyclotriphosphazene, wherein the three phosphorous atoms of the cyclotriphosphazene ring are modified with six phenoxy or aryloxy groups. The cyclotriphosphazene component serves as a curing agent of the epoxy resin. Similarly, U.S. Pat. No. 4,614,788 to Dettloff, et al. discloses an epoxy resin cured by a cyclotriphosphazene compound such as hexakis(n-propylamino) cyclotriphosphazene. The resin reportedly has an enhanced glass transition temperature (Tg) value compared to a similar composition without the phosphazene compound.
U.S. Pat. No. 4,405,738 to McNeely, et al. discloses polyester polymers and copolyester polymer compositions incorporating cyclotri- or cyclotetra-phosphazenes. The modifying groups on the cyclotriphosphazene or cyclotetraphosphazene ring are six or eight dialkylphosphinylmethylenoxy groups. Halogen-substituted tricyclophosphazene compounds also have been added to polymers such as polyamides and polyolefins, as disclosed in U.S. Pat. No. 4,029,634 to Meredith, et al. U.S. Pat. No. 5,344,501 to Hashimoto et al. discloses a solar cell which includes a protective layer formed by polymerizing cyclotriphosphazene. These patents describe cyclophosphazenes as adducts, epoxy resin curing agents or solar cell protective materials. As adducts of polymer compositions, the cyclophosphazenes probably retain their respective free chemical compositions and structures. However, as curing agents or solar cell protective materials, cyclophosphazenes probably polymerize during the application process, destroying the cyclic structure of cyclophosphazene molecules. The reactions of cyclophosphazenes in these references probably produce linear polyphosphazenes. It would be advantageous to produce polymer composition with cyclophosphazenes while retaining the cyclic structure of cyclophosphazene molecules.
It is therefore an object of the present invention to provide new polymer compositions having various organic or inorganic functionalities and, thus, having different chemical and physical properties.
It is another object of the present invention to provide synthetic methods for the preparation of polymer compositions incorporating cyclotriphosphazene groups.
Polymer compositions and methods for their synthesis are provided wherein the compositions include a polynorbornene backbone and pendant cyclotriphosphazene groups, having the formula 
wherein R1 is C1-C10 alkyl, C1-C10 haloalkyl, C3-C6 cycloalkyl, phenyl, substituted phenyl, aryl, xe2x80x94(CH2CH2OCH2CH2)nOCH3 in which n is a positive integer, aminoalkyl, alkoxyalkyl, phenoxyalkyl, aryloxyalkyl and amidoalkyl; and
wherein R2, R3, R4, R5, R6, R7, R8 and R9 are groups selected from the group consisting of H, CH3, X which is a halo group, and C2-C6 alkyl, C3-C6 cycloalkyl, C2-C6 alkoxy, phenoxy, and aryloxy.
In a preferred embodiment, R1 is either xe2x80x94CH2CF3, phenyl, 4-ethylcarboxylatophenyl, xe2x80x94CH2CH3, or xe2x80x94CH2CH2OCH2CH2OCH3. In another preferred embodiment of the polymer composition, R2, R3R4, R5, R6, R7, R8 and R9 are H.
The polyphosphazene compositions can be prepared via ring-opening-metathesis-polymerization of an olefin having norbornene structure with pendant cyclotriphosphazene groups. The polyphosphazene compositions described herein are useful as elastomers, optical materials, electrically conductive materials, biomedical materials, compatibilizing agents, surfactants, additives for coatings, and flame retardants.